What is flagging?
Flagging or reporting is when you mark a question or an answer for review. If a question or answer on wikianswers is inappropriate or vandalized and full of spam you can request it be looked at by a supervisor who has the power to delete it if necessary.
In WikiAnswers, flagging is a way to indicate there are problems with a question or abuse of the site. The system and concerned users can flag questions or answers that need work. Then when users or supervisors fix the problem, the flags can be removed.